The Raiders later confirmed Branch signed his tender worth a reported $6.2 million and returned to workouts with the team.
He remains hopeful of signing a long-term deal. Branch also will begin taking part in the team's offseason program.
Getting Branch signed and with the team was important for the Raiders, who are counting on him to be one of the defensive leaders under a new defense run by head coach Dennis Allen and coordinator Jason Tarver.
Branch, a fourth-round pick in 2008, has started every game the past three seasons and led the Raiders in tackles the past two years. He had 109 tackles, one sack and one interception last season for Oakland.
Branch and free safety Michael Huff will anchor an overhauled secondary in Oakland this year. After years of running a defense premised on aggressive man coverage under late owner Al Davis, the Raiders are expected to use more blitzes and zone coverages this season.
Follow Jason La Canfora on Twitter @JasonLaCanfora.
The Associated Press contributed to this report.